Systems have been developed for matched mailing. Matched mailing as defined herein means that items to be inserted into an envelope are matched with a particular envelope or with other documents. These matched mailings are used, for example, in connection with inserting pre-identified coupons into pre-determined envelopes such that usage patterns of recipients of a mailing can be determined by how the particular coupons are redeemed. Matched mailing systems are also employed where a particular insert such as a letter is to be inserted into an opaque envelope (that is where the inserted letter does not serve as the address bearing document which is visible through a windowed portion of the envelope).
One known method for accomplishing matched mailings has involved the use of relatively expensive optical character recognition (OCR) devices. The name and address on the envelope is read and compared with the name and address on the insert which is also read to insure that the appropriate match exists. OCR devices usually include a scanner for digitizing printed characters, and a computer which executes algorithms for character recognition of the scanned characters. The various types of algorithms include preprocessing algorithms, such as line segmentation, character segmentation, and character recognition algorithms, such as template matching, are well known in the art. In general, the template matching algorithm, in which a scanned character is correlated with templates of all expected characters, is time consuming and normally executed in hardware, which results in expensive systems.
Other known methods of achieving matched mailing involve keeping a track of the location of both the envelope and the insert as the envelope and insert are processed by the system. Another method involves an on-line fabrication of the envelope such that a match is automatically guaranteed. Yet another method involves an on-line address printing on the envelope immediately prior to insertion. These methods are either very costly or are subject to errors.
In U.S. patent application Ser. No. 176,803, filed Apr. 1, 1988, having the same inventor and assignee as the present application, a method and apparatus for matching uniquely identified documents to an envelope using a plurality of bar code readers is disclosed. A bar code reader is mounted on each of the feeder hoppers of an inserter system for the purpose of reading bar code information printed on each document fed onto a transport deck.